Reference:Ballard1998a
Verbatim text: Ballard, H. E., K. J. Sytsma, and R. R. Kowal. 1998. Shrinking the violets: Phylogenetic relationships of infrageneric groups in Viola (Violaceae) based on internal transcribed spacer DNA sequences. Syst. Bot. 23: 439–458.
Author: Ballard, H.E., Sytsma, K.J., Kowal, R.R.
Year: 1998
Title: Shrinking the violets: Phylogenetic relationships of infrageneric groups in Viola (Violaceae) based on internal transcribed spacer DNA sequences
Journal: Syst. Bot
Volume: 23
Pages: 439–458